posted on 2020-03-11, 17:03authored byJuchan Lee, Ngoc Thanh Duong, Seungho Bang, Chulho Park, Duc Anh Nguyen, Hobeom Jeon, Jiseong Jang, Hye Min Oh, Mun Seok Jeong
We
study the electronic and optoelectronic properties of a broken-gap
heterojunction composed of SnSe2 and MoTe2 with
gate-controlled junction modes. Owing to the interband tunneling current,
our device can act as an Esaki diode and a backward diode with a peak-to-valley
current ratio approaching 5.7 at room temperature. Furthermore, under
an 811 nm laser irradiation the heterostructure exhibits a photodetectivity
of up to 7.5 × 1012 Jones. In addition, to harness
the electrostatic gate bias, Voc can be
tuned from negative to positive by switching from the accumulation
mode to the depletion mode of the heterojunction. Additionally, a
photovoltaic effect with a fill factor exceeding 41% was observed,
which highlights the significant potential for optoelectronic applications.
This study not only demonstrates high-performance multifunctional
optoelectronics based on the SnSe2/MoTe2 heterostructure
but also provides a comprehensive understanding of broken-band alignment
and its applications.